Does the addition of convex uniplanar screws in hybrid constructs improve 3D surgical correction in thoracic adolescent idiopathic scoliosis posterior fusion?

Purpose

Hybrid techniques using thoracic sublaminar bands have proved their efficacy in adolescent idiopathic scoliosis posterior fusion, but clinical axial correction sometimes remained disappointing. One solution found was "the frame technique" and the second alternative was the replacement of the convex sublaminar bands by periapical uniplanar screws. The goal of this study was to compare clinical and radiological outcomes of both techniques in a consecutive cohort of adolescent idiopathic scoliosis patients.

Methods

All patients undergoing primary posterior fusion for thoracic adolescent idiopathic scoliosis between January 2017 and March 2020 were included. Two groups were compared: Group 1 with thoracic sublaminar bands only and Group 2 with periapical uniplanar screws. All patients underwent standing stereoradiographs. The main frontal, sagittal, and axial (apical vertebra rotation) radiological parameters of interest were analyzed. Functional outcomes were assessed using the Scoliosis Research Society 30 score.

Results

A total of 147 adolescents were included (Group 1, n = 73 and Group 2, n = 74 patients). In the frontal plane, a greater reduction index was observed in Group 2 (68% versus 62%, p < 0.001) as well as a better apical axial correction (67.8% versus 46.6%, p = 0.03). The number of thoracoplasty performed was reduced (6.7% versus 20.5%, p = 0.02) in Group 2, with a significant decrease in the rate of mechanical complication. No significant loss of correction was observed during follow-up in any of the group.

Conclusion

The adjunction of convex uniplanar screws at the periapical levels improved the three-dimensional surgical correction of thoracic adolescent idiopathic scoliosis treated with hybrid constructs.

Level of evidence

level III, retrospective comparative study.

Is scoliosis a source of pain?

Purpose

Pain in scoliosis is definitely a hot topic with growing popularity. The literature remains very controversial, with a pain prevalence ranging from 23% to 90%, but this can be explained by the great heterogeneity of the numerous series. The aim of this review was to report results from the literature regarding pain in relation to scoliosis regardless of the etiology.

Methods

A bibliographic search in Medline and Google database from 2003 to March 2023 was performed. Relevant literature was analyzed, summarized, and discussed based on authors' experience. A 1-year prospective series of adolescent idiopathic scoliosis patients was also included to compare with the existing literature.

Results

A total of 126 adolescent idiopathic scoliosis patients were included, with a mean preoperative Cobb angle of 64.5° (range, 45°-112°). Reported pain prevalence was 34.1%. Pain and no-pain groups were very different in their self-reported experience, with a very low mean visual analogue scale score of 0.5 (± 0.6) in the no pain group, while visual analogue scale averaged 5.6 (± 1.2) in the pain group (p < 0.001). No significant difference was found between groups regarding the most relevant demographic and radiological parameters.

Conclusion

Evidence-based literature on "scoliosis as a source of pain" remains ambiguous. There seems to be a consensus on the lack of direct relationship between deformity magnitude and back pain intensity. A comprehensive evaluation of the patient is therefore necessary before any treatment, including medical history, clinical examination, and relevant imaging for any child with scoliosis and back pain.

Level of evidence

Level VI.

Bivertebral pedicle-supralaminar autostable claw for proximal fixation of magnetic growing rods in early-onset scoliosis

BACKGROUND

The various methods for the proximal fixation of magnetic growing rods in patients with early-onset scoliosis (EOS) are associated with high rates of mechanical complications related to material failure or proximal junctional kyphosis (PJK). The bivertebral autostable claw (BAC) has been proven reliable in adolescent idiopathic scoliosis but has not been assessed when used with magnetic growing rods. The objective of this study was to describe the operative technique and outcomes of BAC proximal fixation of magnetic growing rods in children with EOS.

HYPOTHESIS

The BAC provides stable and effective proximal fixation in children with early-onset scoliosis.

MATERIAL AND METHODS

This retrospective observational study included 24 patients who had surgery in 2015-2019 for early-onset scoliosis with magnetic growing rod implantation and BAC proximal fixation. Radiological variables were measured in the coronal and sagittal planes before surgery, during the early postoperative period (<3months) and at last follow-up (≥2years).

RESULTS

No neurological complications were recorded. At last follow-up, four patients had radiological PJK, including one patient with clinical PJK due to material failure.

DISCUSSION

BAC proximal fixation is both effective and sufficiently stable (4.2% pull-out) to withstand the forces applied during distraction sessions and daily activities in children with EOS. Moreover, the polyaxial connecting rods ensure better BAC adaptation to the local proximal kyphosis, which is often marked in this population.

CONCLUSION

The BAC is a reliable proximal fixation device that is well-suited to magnetic growing rod fixation in children with EOS.

LEVEL OF EVIDENCE

IV, retrospective observational cohort study.

Slipped Capital Femoral Epiphysis in Adolescents: Functional Outcomes and Return to Physical Activity after Surgical Treatment

Background: Slipped capital femoral epiphysis (SCFE) represents a relatively common hip disorder in adolescents. The present retrospective study analyzes the correlation between age, severity of the slip and physeal stability and the functional outcomes, as well as the ability to return to previous physical activity (PA) of patients surgically treated with either pining in situ (PIS) or the modified Dunn (MD) procedure (anatomical reduction of the slipped epiphysis). Methods:The present research is a retrospective observational study of patients surgically treated for SCFE from 2010 to 2015. The sample was divided into two groups: those treated with PIS and those with the MD procedure. Univariate and multivariate logistic regression analyses were performed to determine the relationship between age, Loder classification (stable/unstable), as well as Southwick slip angle (severity of the slip) to return to previous PA. Furthermore, linear regression was used to investigate the association of the above predictor variables to Oxford and Harris hip scores (HHS). Results:A total of 32 patients were identified (16 treated with PIS and 16 with the MD procedure). None of the examined predictor variables (age, Southwick slip angle, Loder classification) had statistically significant effect on the ability to return to previous PA in either the in situ or Dunn group. Univariate analysis showed that higher patients' age at the time of surgery was related to worse HHS and Oxford scores in both the PIS and MD groups. Unstable hips seem to affect unfavorably the HHS. Conclusion:The present study did not reveal any relationship between the age, degree of the Southwick slip angle, the stability of the physis, and the return to PA. Exploration of additional confounding factors are warranted to better understand the physis-related impact on the functional outcomes in both groups.

A gait functional classification of adolescent idiopathic scoliosis (AIS) based on spatio-temporal parameters (STP)

BACKGROUND

Therapeutic decisions for patients with adolescent idiopathic scoliosis (AIS) are mostly based on static measurements performed on two-dimensional standing full-spine radiographs. However, the trunk plays an essential role in the human locomotion, and the functional consequences during daily activities of this specific and common spinal deformity are not factored in.

RESEARCH QUESTION

Does patients with AIS have specific gait patterns based on spatio-temporals parameters measurements ?

METHODS

90 AIS patients (aged 10-18 years) with preoperative simplified gait analysis were retrospectively included for analysis between 2017 and 2020. Spatio-temporal parameters (STP) were measured on a 3-m baropodometric gaitway and included the measurement of 15 normalized gait parameters. A hierarchical cluster analysis was performed to identify group of patients based on the similarities of their gait patterns, and functional variables' inter-group differences were also measured. The subject distribution was calculated to identify the structural characteristics of the subjects according to their gait patterns.

RESULTS

Three gait patterns were identified. Cluster 1 (46%) was defined by asymmetry, Cluster 2 (16%) by instability, and Cluster 3 (36%) by variability. Each cluster was significantly different from the other ones on at least 6 different parameters (p < 0.05). Furthermore, each cluster was associated with one type of curve: Lenke 1 for Cluster 1 (57.5%), Lenke 6 for Cluster 2 (40%) and Lenke 5 for Cluster 3 (43.5%).

SIGNIFICANCE

Patients with severe AIS have a dynamic signature during gait identified on STP. Understanding consequences of this deformity on gait may be an interesting avenue to study the pathological mechanisms involved in their dynamic motor organization. Furthermore, these results might also be a first step to study the effectiveness of the different therapies.

Descriptive analysis of pediatric orthopedic surgical emergencies during the COVID-19 lockdown: Single-center observational study in a pandemic red-zone area in France

INTRODUCTION

Lockdown involved strict confinement of children at home, radically affecting their way of life, with increased risk of domestic accidents and the temptation to step outside of the legal framework. The aim of the present study was to analyze the impact of lockdown on pediatric emergency turnover in a university reference center situated in a high-risk "red zone" and to describe specific management measures.

HYPOTHESIS

Pediatric emergency turnover and the corresponding lesion mechanisms were altered by lockdown.

MATERIALS AND METHODS

All children undergoing emergency orthopedic surgery during lockdown (group 1) were prospectively included, then retrospectively compared to series operated on during the same period in the previous 3 years. Demographic and surgical data were analyzed, and the pathway changes that were developed were detailed.

RESULTS

Turnover fell by a mean 33.5%, without change in indications. The most frequent lesions were wounds (54.3%), followed by fractures (34.3%) and infections (11.4%); the upper limbs were involved in 84.6% of cases. Lockdown had been infringed in 9.7% of traumas, mainly concerning fractures (55%). Postoperative management was modulated during lockdown in 34% of cases, without complications at the time of writing.

DISCUSSION

Pediatric emergency turnover decreased, without major change in lesion mechanisms. Accidents associated with lockdown infringement were rare (<10%), demonstrating good adaptation on the part of these children living in an urban area. The adapted care pathway was beneficial, and will no doubt continue to optimize management in future, with accelerated circuits and use of telemedicine.

LEVEL OF EVIDENCE

IV, comparative retro-prospective study.

[Descriptive analysis of pediatric orthopedic surgical emergencies during the COVID-19 lockdown: Single-center observational study in a pandemic red-zone area in France]

Introduction

Le confinement a imposé un maintien strict des enfants à domicile, modifiant considérablement leur mode de vie avec un risque accru d’accidents domestiques et la tentation de désobéir au cadre légal. L’objectif était d’analyser l’impact du confinement sur l’activité d’urgence pédiatrique dans un centre universitaire de référence situé en zone rouge, et de décrire les modes de prise en charge spécifiques.

Hypothèse

L’activité chirurgicale d’urgence ainsi que les mécanismes lésionnels en orthopédie pédiatrique ont été modifiés par le confinement.

Matériels et méthodes

Tous les enfants pris en charge au bloc opératoire pour une urgence orthopédique pendant le confinement (groupe 1) ont été inclus de façon prospective, puis comparés de manière rétrospective aux patients opérés lors des mêmes périodes les 3 années précédentes. Les données démographiques et chirurgicales ont été analysées, et les circuits spécifiques instaurés ont été décrits.

Résultats

Une diminution moyenne de 33,5 % de l’activité a été constatée, sans modification des motifs de prise en charge. Les lésions les plus fréquentes étaient les plaies (54,3 %), suivies des fractures (34,3 %) et des infections (11,4 %) et concernaient le membre supérieur dans 84,6 % des cas. Le cadre légal était non respecté dans 9,7 % des traumatismes et occasionnant principalement des fractures (55 %). La prise en charge postopératoire a été modifiée durant le confinement dans 34 % des cas, sans complication à ce jour.

Discussion

Nos résultats ont retrouvé une diminution de l’activité d’urgence pédiatrique sans modification majeure des mécanismes lésionnels. Les accidents survenant en dehors du cadre légal sont demeurés rares (<10 %), témoignant de la bonne adaptation des enfants vivant en zone urbaine. L’adaptation du parcours patient qui a été utile pendant le confinement, a été efficace, et va sans doute permettre de continuer à optimiser la prise en charge dans le futur, avec des circuits raccourcis et la télémédecine.

Niveau de preuve

IV ; Étude comparative rétroprospective.

Benefit - risks analysis of thoracoplasty in adolescent idiopathic scoliosis treated by sublaminar bands

INTRODUCTION

Cosmetic concerns are one of the main complaints of patients with adolescent idiopathic scoliosis (AIS). Several studies have shown a significant improvement in self-image scores after thoracoplasty. However, the effects of thoracoplasty on pulmonary function and clinical outcomes remain debated. The objective was to analyze the benefits and risks of thoracoplasty during AIS surgery using a hybrid construct with sublaminar bands.

MATERIAL AND METHODS

In this monocentric prospective cohort study, 68 patients with thoracic AIS were consecutively included between 2016 and 2017. All patients had low-dose 3D radiographs. Surgical correction was performed via the posterior approach, using the posteromedial translation technique with a hybrid construct (thoracic sublaminar band and lumbar pedicle screws). A thoracoplasty was proposed in cases of severe rib hump (more than 3 cm). Pulmonary function was assessed by pulmonary function tests (PFT) with forced vital capacity, forced expiratory volume in 1 second and total lung capacity). Radiographic parameters and PFT were compared between patients who had or had not had a thoracoplasty preoperatively and 2 years postoperatively. The SRS-22 score was collected at follow-up.

RESULTS

The average age was 15 ± 3 years. Nineteen patients (27%) had a thoracoplasty. The demographic, radiographic and respiratory data of the 2 groups were comparable preoperatively. The correction was similar between the groups on sagittal and coronal views. At 2 years, the PFTs were comparable to those performed preoperatively and no difference was found between the groups. None of the 12 patients who had a pleural effusion had it drained. The total SRS-22 score and the cosmetic subscore were higher in the thoracoplasty group (p<0.03).

DISCUSSION

The association of a thoracoplasty with AIS surgery improves the self-image of patients without altering the PFTs at 2 years postoperatively. Given the low morbidity of thoracoplasty, it seems reasonable to offer it to patients with severe rib hump and high cosmetic demands.

LEVEL OF EVIDENCE

III.

Does the use of intrawound povidone-iodine irrigation and local vancomycin powder impact surgical site infection rate in adolescent idiopathic scoliosis surgery?

PURPOSE

Surgical site infection (SSI) is a major complication after adolescent idiopathic scoliosis (AIS) surgery, with an incidence ranging from 0.5 to 7%. Intraoperative wound decontamination with povidone-iodine (PVP-I) irrigation and/or vancomycin powder in adult spinal surgery has gained attention in the literature with controversial results. The aim of this study was to investigate the impact of using intrawound PVP-I irrigation and local vancomycin powder (LVP) on the incidence of early SSI in AIS surgery.

METHODS

All AIS patients who underwent posterior spinal fusion between October 2016 and December 2019 were retrospectively reviewed. The incidence of early SSI was reported and compared between 2 groups defined by the treating spinal surgeons' preferences: group 1-intrawound irrigation with 2L of PVP-I and application of 3 g LVP before closure and control group 2-patients that did not receive either of these measures.

RESULTS

Nine early cases of SSI (2.9%) were reported among the 307 AIS posterior spinal fusion patients. Incidence of SSI in group 1 (2/178 = 1.1%) was significantly lower than in group 2 (7/129 = 5.4%; p = 0.04). There were no adverse reactions to the use of PVP-I and LVP in our study. At latest follow-up, rate of surgical revision for mechanical failure with pseudarthrosis was significantly lower in group 1 (2/178 = 1.1%) than in group 2 (9/129 = 7.0%; p = 0.01).

CONCLUSION

Intraoperative use of intrawound PVP-I irrigation and vancomycin powder is associated with a significant reduction of early SSI after AIS spine surgery.

LEVEL OF EVIDENCE IV

Retrospective study.

Posterior vertebral column resection for pediatric rigid spinal deformity

INTRODUCTION

Surgery for pediatric spinal deformity may involve vertebral osteotomies in complex cases. Vertebral column resection (VCR) is the most technically demanding procedure, with the severest morbidity. It can use a double anterior and posterior approach (APVCR), though a single posterior approach (PVCR) is gaining in popularity.

HYPOTHESIS

PVCR provides effective correction with acceptable morbidity in children.

METHOD

A single-center retrospective series included spinal deformities treated by PVCR. Surgical data and global pelvic-spinal balance parameters were analyzed.

RESULTS

Sixteen PVCRs were performed in 13 patients, with a mean age of 14.1±2.8 years. Mean operative time was 411±54minutes. Mean preoperative rigid principal Cobb angle was 74.3°. Mean correction was 64.3% postoperatively, without significant correction loss at last follow-up. Mean blood loss was 941±221ml. The cell-saver enabled 92.3% autologous transfusions, with 53.4% homologous transfusions. Transient monoplegia and permanent psoas deficit were observed during the postoperative period. Radiologic follow-up found 4 non-unions requiring revision.

CONCLUSION

PVCR provided major correction of rigid spinal deformity in children. Complications mainly comprised mechanical or neurological incidents.

LEVEL OF EVIDENCE

IV, non-comparative cohort study.

Surgical outcomes of spinal osteochondroma in children: A multicentre observational study

BACKGROUND

Spinal osteochondroma (or exostosis) is a rare benign tumour whose clinical manifestations are delayed due to their slow growth and location. Few studies have addressed the characteristics and the diagnostic and therapeutic peculiarities of spinal osteochondroma in children. The objective of this multicentre observational study was to assess the outcomes of a cohort of children after surgery for spinal osteochondroma.

HYPOTHESIS

Surgical excision of spinal osteochondroma in children is not followed by complications or recurrences.

MATERIAL AND METHODS

We included consecutive children who had surgery between 2010 and 2018 at any of eight participating centres to remove spinal osteochondromas. The cause, clinical manifestations, and location of the lesions were collected. The surgical outcomes were evaluated after at least 2 years' follow-up.

RESULTS

We identified 22 patients who had surgery to remove 26 spinal osteochondromas at a mean age of 12.8±2.6 years. Among them, 7 had a solitary osteochondroma (SO group) and 15 had hereditary multiple osteochondromas (HMO group). At diagnosis, 72% of patients had clinical signs (spinal pain, n=4; one or more lumps, n=5; and neurological manifestations, n=3). In the HMO group, the diagnosis was made during routine MRI screening for tumours involving the spinal canal. Most osteochondromas involved the cervical spine (n=13), with no difference between the two groups (p=0.9). The lamina was the most common location but 54% of the tumours were growing within the canal (92% in the HMO group). After a mean follow-up of 5.2±4.4 years, no patients had experienced any recurrences or complications related to the disease or treatment.

DISCUSSION

Surgical excision of spinal osteochondromas in children is effective, with no medium-term recurrences. Our results also confirm the low peri-operative morbidity, even when the canal is involved, and the absence of any effect at last follow-up on spinal alignment. All patients with neurological manifestations at diagnosis made a full recovery.

LEVEL OF EVIDENCE

IV, retrospective observational cohort study.

S2-Alar-iliac screw fixation for paediatric neuromuscular scoliosis: Preliminary results after two years

BACKGROUND

Correcting pelvic obliquity is among the main goals of surgery for neuromuscular scoliosis. Spino-pelvic fixation must be stable and capable of withstanding the considerable mechanical forces applied at the lumbo-sacral junction. Selection of the best anchoring option is therefore crucial. S2-alar-iliac (S2AI) screws, which are used in adults, are less often chosen in the French paediatric spinal-surgery community. The objective of this study was to report our preliminary experience with S2AI screws used in the treatment of paediatric patients with neuromuscular scoliosis.

HYPOTHESIS

Pelvic anchoring by means of S2AI screws is reliable and technically feasible in non-ambulatory children with neuromuscular scoliosis.

MATERIALS AND METHODS

Consecutive non-ambulatory patients who underwent scoliosis surgery with S2AI screw fixation to the pelvis between 2016 and 2018 were retrospectively included. The surgical procedure consisted in either posterior spinal fusion (PSF) or magnetic growing rod (MGR) implantation. In all patients, radiographs were obtained before surgery, within 3 months after surgery, and at last follow-up; and low-dose computed tomography (CT) was performed before and after surgery.

RESULTS

We included 25 patients with a mean age of 13.8±4.0 years, 18 managed by PSF and 7 by MGRs. Screw diameters ranged from 7.5 to 9.5mm and all screws were at least 60mm in length. The diameters and lengths were the same on both sides in 16 (89%) patients in the PSF group and in all patients in the MGR group. At last follow-up after a mean of 35.5±3.0 months, pelvic obliquity was corrected in all 23 patients with this abnormality before surgery. Complications consisted of lateral cortical screw breakthrough in 8 (32% of screws) patients and screw malposition in 2 (8% of screws) patients. No clinically significant complications related to the fixation material were recorded.

DISCUSSION

The results of our study demonstrate the feasibility of S2AI screw fixation in paediatric patients with neuromuscular scoliosis. Pelvic asymmetry and dysmorphism do not contra-indicate the procedure but must be evaluated before surgery. Further work is needed to assess the potential long-term consequences on pain and growth of screw passage through the sacro-iliac joints.

LEVEL OF EVIDENCE

IV, retrospective study.

Study of the latency of transcranial motor evoked potentials in spinal cord monitoring during surgery for adolescent idiopathic scoliosis

OBJECTIVE

An increase in the latency of a motor evoked potential might be as significant as a decrease in amplitude to predict a significant and clinically symptomatic neurological injury in spinal surgery for adolescent idiopathic scoliosis. The aim of the study was to investigate the impact of monitoring of latency of motor evoked potentials during spinal surgery for adolescent idiopathic scoliosis by describing intraoperative data.

METHODS

Preoperative recordings of 50 patients undergoing posterior spinal fusion for idiopathic scoliosis were studied. Latencies of appearance of the motor evoked potential curves on the right and left side were recorded for each group of muscles at several key moments during the procedure (basal, before the first implant, before and after corrective maneuvers).

RESULTS

Mean latencies were approximately the same in each muscle group on the right and the left side, before and after correction. There was no significant increase in latency during surgery. Overall results showed that the measured latency did not differ significantly between the two age groups (p=0.07). Negative correlation between height and the means of latencies was recorded in the abductor pollicis brevis and abductor digiti minimi (r=0.4; p=0.009), rectus femoris (r=0.4; p=0.01), tibialis anterior (r=0.4; p=0.007), and abductor hallucis (r=0.5; p=0.0004). No significant correlation was found between age and intraoperative parameters.

CONCLUSION

Intraoperative latency could be a reliable intraoperative monitoring criteria with low variability, that might be used to predict postoperative motor deficits in surgery for adolescent idiopathic scoliosis.

Post-traumatic Radioulnar Synostosis in Distal Forearm Fractures in Children: A Report of 2 Cases

CASES

Two pediatric cases of post-traumatic distal radioulnar synostosis are reported, accompanied by a literature review summarizing evidence on the management of these conditions. Radioulnar synostosis is a rare complication of distal forearm fractures, which impairs upper-extremity function. The numerous surgical procedures that have been described to treat this condition in adults typically involve synostosis resection and an interposition graft to reduce recurrence. The optimal treatment in children has not been established.

CONCLUSIONS

Post-traumatic radioulnar synostoses are rare conditions in pediatric patients who can be successfully treated with surgical excision of the synostoses and without the use of interposition grafting.

Is anterior subcapital shortening osteotomy a reliable and reproducible technique in the treatment of severe slipped capital femoral epiphysis?

INTRODUCTION

Proximal femoral shortening osteotomies are becoming the treatment of choice for severe slipped capital femoral epiphysis (SCFE) to reduce the risk of femoroacetabular impingement. The reported rates of complication seem reasonable, but these are single-operator series with surgeons highly experienced in this technique. The purpose of this study was to assess how surgeon experience impacted the outcomes of anterior subcapital shortening osteotomy (ASSO) in severe SCFE.

HYPOTHESIS

The hypothesis was that ASSO is a reproducible technique that is accessible to junior surgeons.

MATERIALS AND METHODS

All ASSOs performed for severe SCFE (slipangle > 40°) between 2015 and 2019 were retrospectively reviewed. All osteotomies were performed by surgeons with less than 4 years' experience (senior residents), who were trained by a senior surgeon experienced in this technique (Group 1). The incidence of femoral head avascular necrosis (AVN) and complications were analyzed and compared to a historical control cohort (Group 2).

RESULTS

A total of 62 SCFEs (37 unstable and 25 stable) were analyzed. Both groups had similar demographic data and SCFE characteristics. The mean operative times were statistically comparable in both groups. The rates of AVN in unstable SCFEs and in the overall series were comparable in both groups (18.9% vs. 13.3%, p=.55 and 12.9% vs. 9.7%, p=.6). These rates were comparable in the stable forms (4.0% vs. 5.4%; p=1). However, the preoperative MRI in Group 1 showed that 42.8% of unstable hips that developed AVN were already hypoperfused before surgery. The overall rate of complication showed no significant difference between the 2 groups (26% vs. 17%, p=.16).

DISCUSSION

Although ASSO is a technically demanding procedure, it is reliable and reproducible. The main risk factor for developing AVN remains the unstable nature of SCFE and not the surgeon's experience. It can be performed by trained junior surgeons, but not in an emergency setting, with the possibility of assistance from a more experienced surgeon.

LEVEL OF EVIDENCE

IV; retrospective case study.

Is magnetic resonance imaging reliable for assessing osteosarcoma of the knee joint in children?

INTRODUCTION

The study of tumor extension in knee osteosarcomas is an essential diagnostic tool that helps determine the surgical approach. Magnetic resonance imaging (MRI) is the key component in this decision-making process, but the interpretation of signals can be difficult because peritumoral edema and inflammation may be mistaken for the tumor.

HYPOTHESIS

There is a discrepancy between MRI and histopathology findings in the assessment of joint involvement in pediatric osteosarcomas of the knee.

MATERIALS AND METHODS

All children who underwent an extra-articular resection for an osteosarcoma of the knee between 2007 and 2016 were included. This was indicated if there was at least one of the following MRI signs: presence of articular effusion, involvement of either the peripheral capsuloligamentous structures, central pivot or patella, or lesion abutting the articular cartilage.

RESULTS

Nine patients were operated on with a mean age of 13±2.7 years. There were at least two of the described signs, mainly the involvement of the peripheral capsuloligamentous structures (78%) and central pivot (56%). The histopathology confirmed that the resection margins were healthy in all cases, but the indication for extra-articular resection could have been avoided in 89% of them.

DISCUSSION

MRI is the current gold standard for assessing tumor extension, but the signs contraindicating the transarticular approach remain poorly defined. Joint effusion detected by clinical or radiological assessment is the least reliable one. It seems that the tumor's proximity to the articular cartilage, as long as there is no loss of continuity in the latter, or its extension into the central pivot should no longer be considered as relevant signs. The involvement of the peripheral capsuloligamentous structure remains an indication criterion because oncologic resection is otherwise impossible, and the risk of false-negative histopathologic diagnoses is higher. Other MRI sequences could better assess the true extension into the joint space.

LEVEL OF EVIDENCE

IV, retrospective study.

Halo-gravity traction followed by definitive fusion in severe early onset scoliosis: results of a trunk analysis based on biplanar 3D reconstructions

PURPOSE

Definitive fusion can be considered in early onset scoliosis (EOS) around triradiate cartilage closure. Halo-gravity traction (HGT) is an old strategy that can help lengthen and balance the spine before fusion. The postoperative changes of the trunk have never been investigated to date with modern imaging. The goal of this study was to analyze the 3D radiological outcomes, and the associated pulmonary function, of a cohort of severe EOS patients treated by definitive posterior fusion prepared by HGT.

METHODS

All consecutive EOS patients with severe (> 85°) and stiff (flexibility < 25%) curves, treated by HGT followed by posterior fusion, were followed. 3D radiological measurements and pulmonary function were assessed.

RESULTS

Forty-nine EOS patients underwent fusion, with a mean follow-up of 4 years (± 1). Age at surgery averaged 13.5 years old. HGT protocol reached on average 41% of body weight. Mean preoperative 3D Cobb angle was 95° (± 10) and final correction averaged 68.4% after surgery. 3D T4T12 kyphosis was reduced after surgery (11°, p < 0.01), while the apical vertebral rotation was improved by 27.8% (p = 0.06). 3D thoracic volume increased after surgery (p = 0.02), with a 3D T1T12 height gain averaging 3.7 cm (± 2). Both parameters were significantly correlated with total lung capacity improvement. Seven complications (14.2%) were reported, and 5 patients (10.6%) underwent unplanned revision.

CONCLUSION

HGT is a safe and efficient strategy to prepare posterior fusion in severe EOS patients. The 3D trunk analysis demonstrated significant postoperative gains in thoracic and spinal lengths, as well as in thoracic volume.

LEVEL OF EVIDENCE

IV.

The functional method: experience from the Robert Debré Hospital

Background

In the 1970s a conservative treatment for clubfoot (CF) deformity based on daily physiotherapy combining specific sequences was developed: the French functional method (FFM). Over time, the FFM technique has improved and additional measures have been introduced. The aim of this study was to report mid-term and long-term results of clubfeet treated conservatively by the FFM at birth.

Methods

All patients consecutively treated for clubfoot by the FFM between 1993 and 2010 were prospectively included. Initial severity was assessed by the Dimeglio classification. All patients were followed up by the same treating surgeon until skeletal maturity. Final assessment was performed using the International Clubfoot Study Group evaluation system (ICFSG).

Results

A total of 779 feet were included. Surgery was required in 41% of cases (mean age 2.0±0.1 years). The incidence of surgery significantly decreased after the introduction of percutaneous Achilles tenotomy (PAT) in 2000 (63.4% vs. 29.6%). At latest evaluation (mean follow-up 12±0.2 years), 86% of patients had excellent or good outcomes (mean ICFSG was 1.83±0.1). Mean ankle dorsiflexion was 10° in non-idiopathic CF and 12.1° in idiopathic CF. Eleven percent of the idiopathic clubfeet exhibited decreased ankle function (0–10°). There were no cases of overcorrection into excess ankle dorsiflexion or rocker bottom foot deformities.

Conclusions

Current team was the funding institution of the FFM and several modifications were proposed over times to improve outcomes. Eighty-six percent of feet had excellent to good outcomes according to the ICFSG score, with minimal residual deformities (ankle dorsiflexion between 0° and 10°, calcaneal-thigh angle between 10° and 20°) or insufficient radiological correction (defined by talo-calcaneal angle between 10° and 20°) at latest follow-up.

Effects of opioid-reduced anesthesia during scoliosis surgery in children: a prospective observational study

Aims: Opioid-reduced anesthesia (ORA) was suggested to decrease morphine consumption after adolescent idiopathic scoliosis (AIS) surgery and incidence of chronic pain. Materials & methods: A prospective analysis using the ORA in AIS surgery was performed. Two cohorts were compared: a control group (opioid-based anesthesia) and the ORA group. The main outcome was morphine consumption at day 1. Results: 33 patients operated for AIS using ORA were compared with 36 with opioid-based anesthesia. Morphine consumption was decreased in the ORA group (1.1 mg.kg^-1 [0.2-2] vs 0.8 mg.kg^-1 [0.3-2]; p = 0.02) at day 1. Persistent neuropathic pain at 1 year was decreased in the ORA group (p = 0.02). Conclusion: The ORA protocol is efficient to reduce postoperative morphine consumption in AIS surgery and preventing neuropathic pain.

Guided growth vs.Tibial osteotomy at early stage of Blount disease in squelletically immature patients

BACKGROUND

There are no comparative study between guided growth and tibial osteotomy in early stage of Blount disease (BD) to our knowledge. The aim of this work was to compare the results of patients treated by these two techniques.

METHOD

This was a retrospective, descriptive, and analytical study over a period of 5 years in including 17 children (24 Knees) with an early stage of infantile BD in two centers. Patient were classified in two groups: group 1(treated by guided growth), group 2 (treated by Tibial Osteotomy).Preoperative alignment analysis using the tibial femoral angle (HKA) and the proximal medial tibial mechanical angle (mMPTA) were compared with three measurements taken postoperatively in each of the groups. The mean variations of the angles were compared between the two groups.

RESULTS

Socio-demographic characteristics were similar for the two groups. Median age at surgery was 6.5 ± 2.5 [3-9 years] in group 1 and 6.8 ± 2.9 years [3-9 years]. At a follow-up of 24 ± 3.5 months, the limb alignment was significantly corrected (1,03°/month) in group 1 (median HKA 144°-171°; p = 0,001; median MMPTA 78°-87°, p = 0,018), and in group 2 we observed at a follow-up of 23 ± 15 months a progressive loss (0,52°/month) of the correction obtained immediately postoperatively (median HKA 160°-176°(immediate post operative) to 165,5°; p = 0,31; median MMPTA = 78°-86° (immediate post operative) to 80,5°; p = 0,37).There was a statistically significant difference between the mean variation in HKA between the two groups (group 1 = 22,5; group 2 = 4,5, p = 0.00), as well as for MMPTA; (group 1 = 7; group 2 = 2,5, p = 0,023).The rate of correction was 78% in group 1 with no rebound at a median follow-up after removal of the material of 10 ± 2.4 months. Within group 2, the rate of correction was 10% with a recurrence rate of 60%.

CONCLUSION

Guided growth appears to be the best treatment for early stage of BD in squelletically immature patients.

Acute monoarthritis in young children: comparing the characteristics of patients with juvenile idiopathic arthritis versus septic and undifferentiated arthritis

Acute arthritis is a common cause of consultation in pediatric emergency wards. Arthritis can be caused by juvenile idiopathic arthritis (JIA), septic (SA) or remain undetermined (UA). In young children, SA is mainly caused by Kingella kingae (KK), a hard to grow bacteria leading generally to a mild clinical and biological form of SA. An early accurate diagnosis between KK-SA and early-onset JIA is essential to provide appropriate treatment and follow-up. The aim of this work was to compare clinical and biological characteristics, length of hospital stays, duration of intravenous (IV) antibiotics exposure and use of invasive surgical management of patients under 6 years of age hospitalized for acute monoarthritis with a final diagnosis of JIA, SA or UA. We retrospectively analyzed data from < 6-year-old children, hospitalized at a French tertiary center for acute mono-arthritis, who underwent a joint aspiration. Non-parametric tests were performed to compare children with JIA, SA or UA. Bonferroni correction for multiple comparisons was applied with threshold for significance at 0.025. Among the 196 included patients, 110 (56.1%) had SA, 20 (10.2%) had JIA and 66 (33.7%) had UA. Patients with JIA were older when compared to SA (2.7 years [1.8–3.6] versus 1.4 [1.1–2.1], p < 0.001). Presence of fever was not different between JIA and SA or UA. White blood cells in serum were lower in JIA (11.2 × 10⁹/L [10–13.6]) when compared to SA (13.2 × 10⁹/L [11–16.6]), p = 0.01. In synovial fluid leucocytes were higher in SA 105.5 × 10³ cells/mm³ [46–211] compared to JIA and UA (42 × 10³ cells/mm³ [6.4–59.2] and 7.29 × 10³ cells/mm³ [2.1–72] respectively), p < 0.001. Intravenous antibiotics were administered to 95% of children with JIA, 100% of patients with SA, and 95.4% of UA. Arthrotomy-lavage was performed in 66.7% of patients with JIA, 79.6% of patients with SA, and 71.1% of patients with UA. In children less than 6 years of age with acute mono-arthritis, the clinical and biological parameters currently used do not reliably differentiate between JIA, AS and UA. JIA subgroups that present a diagnostic problem at the onset of monoarthritis before the age of 6 years, are oligoarticular JIA and systemic JIA with hip arthritis. The development of new biomarkers will be required to distinguish JIA and AS caused by Kingellakingae in these patients.

Enhanced recovery after surgical correction of adolescent idiopathic scoliosis

BACKGROUND

Few publications in the literature examine enhanced recovery after scoliosis surgery (ERAS) in children, despite significant scientific interest in adults. The objective of the current study was to describe an ERAS protocol for surgical correction of adolescent idiopathic scoliosis (AIS) and its results.

METHODS

ERAS outcomes were measured in two patient cohorts. Historical controls and ERAS groups were selected from patients managed for scoliosis surgery in 2015 and 2018, respectively. The ERAS protocol included fasting minimization, carbohydrate loading, the avoidance of background morphine infusions, perioperative opioid-sparing protocols, the use of a cooling brace, early physiotherapy, feeding and oral medications, and the early removal of urinary catheters and surgical drains. The main outcome of the study was hospital length of stay.

RESULTS

Overall, 82 controls and 81 ERAS patients were recruited. ERAS protocols were observed in over 80% of patients for almost items. Median length of hospital stay was significantly lower in the ERAS group (- 3 [95% confidence interval: -2; -4] days). Median morphine consumption was reduced by 25% and 35% on days 2 and 3, respectively. The incidence of PONV did not differ between the two groups, and the incidence of constipation decreased slightly but significantly in the ERAS group on day 2. Pain intensity at rest and movement were lower in the ERAS group at day 2 and 3.

CONCLUSIONS

The current study suggests an ERAS protocol after adolescent idiopathic scoliosis surgery is associated with reduced hospital length of stay and improved postoperative care.

Legg–Calvé–Perthes Disease: A Case-based Resident’s Guide for the Pediatric Rotation

The article's abstract is not available.

Correction to: Is Cutibacterium acnes early surgical site infection rate related to the duration of antibiotic prophylaxis in adolescent idiopathic scoliosis surgery?

Unfortunately, the authors first name and family name were incorrectly swapped in the original publication. The complete correct names of the author group is given below.

Is Cutibacterium acnes early surgical site infection rate related to the duration of antibiotic prophylaxis in adolescent idiopathic scoliosis surgery?

PURPOSE

Cutibacterium acnes (C. acnes) is a gram-positive anaerobic bacillus located in pilosebaceous glands, usually responsible for late postoperative surgical site infections (SSI). A recent study performed in our institution highlighted an unexpected emergence of C. acnes early SSI. One potential explanation was the change of the perioperative antibioprophylaxis (ATB) protocol, which switched from 48 h postoperative cefamandole to intraoperative only cefazoline. The aim of this study was therefore to investigate the influence of the ATB duration on the occurrence of C. acnes early SSI, by comparing the incidence rates during 3 consecutive ATB protocols.

METHODS

Between January 2007 and September 2017, all patients who underwent posterior fusion for AIS were retrospectively reviewed. Early C. acnes SSI were reported and compared between 3 periods, during which the ATB protocols were modified. January 2007-February 2012: Intraoperative Cefamandole continued 48 h (protocol 1) March 2012-August 2016: Single shot of intraoperative Cefazoline (protocol 2) September 2016-September 2017: Intraoperative Cefazoline continued 48 h (protocol 3).

RESULTS

Fifty-three early SSI (7.2%) were reported among the 732 posterior AIS fusions included. Global incidence of C. acnes infection was 2.9%. The incidence of C. acnes in early SSI increased from 0 to 4.9% between protocol 1 and 2, but was reduced to 1.7% with protocol 3.

CONCLUSIONS

Early C acnes SSI can be explained by the difficulty to eradicate this pathogen with current skin preparation procedures and some Beta-lactam antibiotics tolerance. Longer duration antibioprophylaxis is preferable to prevent from early C. acnes SSI.

Spinal sagittal alignment and head control in patients with cerebral palsy

PURPOSE

Spinal sagittal alignment restoration has been associated with improved functional outcomes and with reduced complications rates. Several limitations exist for radiological analysis in cerebral palsy (CP) patients. The goal of this study was to summarize the existing literature and report the important considerations to evaluate in a CP patient undergoing spinal surgery.

METHODS

A retrospective radiological analysis was performed, including non-ambulant CP children with progressive scoliosis. Full-spine sitting radiographs performed pre-and postoperatively were required to measure spino-pelvic sagittal parameters.

RESULT

A total of 23 non-ambulating CP patients were included, mean age 16.0 years (standard error of the mean 0.5). Two distinct groups of patients were identified. Group 1 (61%) were patients with less trunk control (lumbar lordosis (LL) < 50°), retroverted and vertical pelvis (mean sacral slope (SS) 11.4° and pelvic tilt (PT) 38.1°) and anterior imbalance (mean sagittal vertical axis (SVA) 5.9 cm) and Group 2 (39%) were patients with better trunk control (LL > 60°, anteverted and horizontal pelvis (mean SS 49.3°, PT 9.7°) and posterior imbalance (mean SVA 5.8 cm). Postoperative measures showed significant impact of surgery with a PT reduction of 19° (p = 0.007), a mean SS increase of 15° (p = 0.04) and a LL gained of 10° (p = 0.2).

CONCLUSION

Sagittal spino-pelvic alignment in non-ambulating CP patients remains difficult to assess. The current literature is poor but our radiological study was able to define two distinct groups among Gross Motor Function Classification System (GMFCS) level V patients, based on the quality of their trunk control. All possible factors that may influence head and trunk posture should be systematically considered and optimized.

LEVEL OF EVIDENCE

Level IV.

Are postoperative standing radiographs relevant before hospital discharge in adolescent idiopathic scoliosis?

PURPOSE

Postoperative standing radiographs are usually performed before hospital discharge after AIS fusion. However, patients are often still painful and have not recovered yet their physiological balance. The aim of this study was therefore to evaluate the relevance of such early radiographs and more specifically investigate whether postoperative alignment could be analyzed.

METHODS

All consecutive AIS patients operated between January 2015 and December 2015 were included. All patients underwent biplanar stereoradiographs before hospital discharge, at 4 months postoperative and at last follow-up. Fifteen parameters (eight coronal and seven sagittal), reflecting correction and spinal alignment were measured and compared. The incidence of implant misplacement, requiring or not surgical revision, was recorded.

RESULTS

In total, 100 patients were included. A significant difference was found for 12 out of the 15 (80%) parameters between the first erect radiograph and the 4-month follow-up visit, including the CVA and the SVA, which are commonly used to assess postoperative alignment. Clavicle, UIV and LIV tilts also decreased significantly at 4 months postoperative. In opposition, no significant change occurred for the same parameters between the 4-month visit and latest follow-up. In nine patients, a pedicle screw was considered misplaced on the first radiograph, but all patients remained asymptomatic and no revision was performed.

CONCLUSION

There is no need for additional immediate postoperative radiographs in AIS, if an intraoperative radiograph has already been taken. This finding could help reducing radiation exposure in immature patients and should be further studied in other etiologies. These slides can be retrieved under Electronic Supplementary Material.

Test-retest reliability of an instrumented electronic walkway system (GAITRite) for the measurement of spatio-temporal gait parameters in young patients with Friedreich's ataxia

BACKGROUND

Friedreich ataxia (FRDA) affects the spatio-temporal parameters (STP) of gait. To our knowledge, proper tools to measure the variability of ataxic gait have not been validated yet. The aims of the present study were: (1) to measure the reproducibility of STP and gait scores in young patients with FRDA and (2) to describe the characteristics of gait parameters in this population.

METHODS

Thirty-six patients (18 males, 18 females) with diagnosis of FRDA (mean age 16.4 ± 4.5 years) were asked to walk barefoot at a self-selected pace along the pressure sensitive walkway (GAITRite^®). Three trials were recorded for each patient and repeated 48 h later. Collected data was put into statistical analysis tests to determine reliability and variability of STPs and two other gait scores: The Functional Ambulation Performance score (FAP) and the Gait Variability Index (GVI).

RESULTS

All STPs showed strong or very strong reliability (ICC > 0.7) and a low variability. The two parameters showing the lowest reliability (0.71 and 0.74) were the base of support and the foot progression angle. The FAP score and the GVI showed strong reliability (ICC > 0.8).

CONCLUSIONS

The GAITRite system allows feasible and reliable measurements of gait parameters in young patients with FRDA. Lower reliability found for the weakest parameters was attributed to the software automatic errors and the ankle laxity noted in every patient.

Does Staphylococcus aureus nasal decontamination affect the rate of early surgical site infection in adolescent idiopathic scoliosis surgery?

PURPOSE

Surgical site infection (SSI) is a main complication after adolescent idiopathic scoliosis (AIS) surgery. Nasal colonization with S. aureus is a known risk factor for developing nosocomial infections in cardiac surgery. However, the risk in orthopedic surgery remains unclear, especially in spine surgery. This study aims to report the efficacy of a preoperative nasal decontamination program in S. aureus carriers on the incidence of early SSI after AIS posterior surgery.

METHODS

Between January 2014 and July 2017, all AIS patients were screened preoperatively with nasal swabs and decontaminated if positive 5 days before surgery. Early SSI was identified, and microorganisms findings were analyzed within nasal carriage and compared to a previous series published before the decontamination program (2007-2011).

RESULTS

Among the 331 AIS posterior fusion performed during the study period, incidence of positive nasal swab was 23% (n = 75). Those were preoperatively decontaminated. In comparison with the period before the nasal decontamination program, incidence of S. aureus early SSI significantly decreased from 5.1 to 1.3%, p < 0.05. None of those S. aureus decontaminated patients had an early S. aureus SSI. In all cases of S. aureus infections, S. aureus nasal screening was negative with a mean delay of 315 days (± 115) before surgery, which was significantly different from the global cohort (104 days ± 67, p < 0.05).

CONCLUSIONS

Preoperative S. aureus nasal decontamination was associated with a significant decrease in S. aureus SSI. Optimal delay of nasal screening needs to be optimized in order to diagnose intermittent S. aureus carriers. These slides can be retrieved under Electronic Supplementary Material.

Preliminary experience with SpineEOS, a new software for 3D planning in AIS surgery

PURPOSE

Preoperative planning of scoliosis surgery is essential in the effective treatment of spine pathology. Thus, precontoured rods have been recently developed to avoid iatrogenic sagittal misalignment and rod breakage. Some specific issues exist in adolescent idiopathic scoliosis (AIS), such as a less distal lower instrumented level, a great variability in the location of inflection point (transition from lumbar lordosis to thoracic kyphosis), and sagittal correction is limited by both bone-implant interface. Since 2007, stereoradiographic imaging system is used and allows for 3D reconstructions. Therefore, a software was developed to perform preoperative 3D surgical planning and to provide rod's shape and length. The goal of this preliminary study was to assess the feasibility, reliability, and the clinical relevance of this new software.

METHODS

Retrospective study on 47 AIS patients operated with the same surgical technique: posteromedial translation through posterior approach with lumbar screws and thoracic sublaminar bands. Pre- and postoperatively, 3D reconstructions were performed on stereoradiographic images (EOS system, Paris, France) and compared. Then, the software was used to plan the surgical correction and determine rod's shape and length. Simulated spine and rods were compared to postoperative real 3D reconstructions. 3D reconstructions and planning were performed by an independent observer.

RESULTS

3D simulations were performed on the 47 patients. No difference was found between the simulated model and the postoperative 3D reconstructions in terms of sagittal parameters. Postoperatively, 21% of LL were not within reference values. Postoperative SVA was 20 mm anterior in 2/3 of the cases. Postoperative rods were significantly longer than precontoured rods planned with the software (mean 10 mm). Inflection points were different on the rods used and the planned rods (2.3 levels on average).

CONCLUSION

In this preliminary study, the software based on 3D stereoradiography low-dose system used to plan AIS surgery seems reliable for preoperative planning and precontoured rods. It is an interesting tool to improve surgeons' practice, since 3D planning is expected to reduce complications such as iatrogenic malalignment and to help for a better understanding of the complications, choosing the location of the transitional vertebra. However, further work is needed to improve thoracic kyphosis planning. These slides can be retrieved under Electronic Supplementary Material.

Supramolecular influence on cis-trans isomerization probed by ion mobility spectrometry

We used tandem ion mobility spectrometry measurements to investigate how the photo-isomerization of a chromophore (a methylpyridinium derivative) is affected by the complexation with a crown ether. A dramatic blue-shift of the photo-isomerization spectrum was observed upon complexation, which could be well reproduced by ab initio calculations. Our results support that the observed changes in the photo-physical properties of the chromophore originate from the charge-solvation of its pyridinium moiety by the host cage.

Temporal Association Between Rhinovirus Activity and Kingella kingae Osteoarticular Infections

OBJECTIVE

To determine whether the seasonal distribution of Kingella kingae osteoarticular infections is similar to that of common respiratory viruses.

STUDY DESIGN

Between October 2009 and September 2016, we extracted the results of K kingae-specific real-time polymerase chain reaction analyses performed for bone or joint specimens in patients from 2 pediatric tertiary care centers in Paris. We used data of respiratory virus detection from the Réseau National des Laboratoires network with coordination with the National Influenza Center of France. The Spearman rank correlation was used to assess a correlation between weekly distributions, with P < .05 denoting a significant correlation.

RESULTS

During the 7-year study period, 322 children were diagnosed with K kingae osteoarticular infection, and 317 testing episodes were K kingae-negative. We observed high activity for both K kingae osteoarticular infection and human rhinovirus (HRV) during the fall (98 [30.4%] and 2401 [39.1%] cases, respectively) and low activity during summer (59 [18.3%] and 681 [11.1%] cases, respectively). Weekly distributions of K kingae osteoarticular infection and rhinovirus activity were significantly correlated (r = 0.30; P = .03). In contrast, no significant correlation was found between the weekly distribution of K kingae osteoarticular infection and other respiratory viruses (r = -0.17, P = .34 compared with respiratory syncytial virus; r = -0.13, P = .34 compared with influenza virus; and r = -0.22, P = .11 compared with metapneumovirus).

CONCLUSION

A significant temporal association was observed between HRV circulation and K kingae osteoarticular infection, strengthening the hypothesis of a role of viral infections in the pathophysiology of K kingae invasive infection.

Clinical experience with a single-nucleotide polymorphism-based non-invasive prenatal test for five clinically significant microdeletions

Single-nucleotide polymorphism (SNP)-based non-invasive prenatal testing (NIPT) can currently predict a subset of submicroscopic abnormalities associated with severe clinical manifestations. We retrospectively analyzed the performance of SNP-based NIPT in 80 449 referrals for 22q11.2 deletion syndrome and 42 326 referrals for 1p36, cri-du-chat, Prader-Willi, and Angelman microdeletion syndromes over a 1-year period, and compared the original screening protocol with a revision that reflexively sequenced high-risk calls at a higher depth of read. The prevalence of these microdeletion syndromes was also estimated in the referral population. The positive predictive value of the original test was 15.7% for 22q11.2 deletion syndrome, and 5.2% for the other 4 disorders combined. With the revised protocol, these values increased to 44.2% for 22q11.2 and 31.7% for the others. The 0.33% false-positive rate (FPR) for 22q11.2 deletion syndrome decreased to 0.07% with the revised protocol. Similarly, the FPR for the other 4 disorders combined decreased from 0.56% to 0.07%. Minimal prevalences were estimated to be 1 in 1255 for 22q11.2 deletion syndrome and 1 in 1464 for 1p36, cri-du-chat, and Angelman syndromes combined. Our results show that these microdeletions are relatively common in the referral population, and that the performance of SNP-based NIPT is improved with high-depth resequencing.

Assessment of stability during gait in patients with spinal deformity-A preliminary analysis using the dynamic stability margin

Daily living activities are dynamic, requiring spinal motion through space. Current assessment of spinal deformities is based on static measurements from full-spine standing radiographs. Tools to assess dynamic stability during gait might be useful to enhance the standard evaluation. The aim of this study was to evaluate gait dynamic imbalance in patients with spinal deformity using the dynamic stability margin (DSM). Twelve normal subjects and 17 patients with spinal deformity were prospectively recruited. A kinematic 3D gait analysis was performed for the control group (CG) and the spinal deformity group (SDG). The DSM (distance between the extrapolated center of mass and the base of support) and time-distance parameters were calculated for the right and left side during gait. The relationship between DSM and step length was assessed using three variables: gait stability, symmetry, and consistency. Variables' accuracy was validated by a discriminant analysis. Patients with spinal deformity exhibited gait instability according to the DSM (0.25m versus 0.31m) with decreased velocity (1.1ms^-1 versus 1.3ms^-1) and decreased step length (0.32m versus 0.38m). According to the discriminant analysis, gait stability was the more accurate variable (area under the curve AUC=0.98) followed by gait symmetry and consistency. However, gait consistency showed 100% of specificity, sensitivity, and accuracy of precision. The DSM showed that patients with spinal malalignment exhibit decreased gait stability, symmetry, and consistency besides gait time-distance parameter changes. Additional work is required to determine how to apply the DSM for preoperative and postoperative spinal deformity management.

Correction: Supramolecular influence on cis–trans isomerization probed by ion mobility spectrometry

Correction for ‘Supramolecular influence on cis–trans isomerization probed by ion mobility spectrometry’ by Izabella Czerwinska et al., Phys. Chem. Chem. Phys., 2016, 18, 32331–32336.

Video-assisted functional assessment of index pollicisation in congenital anomalies

PURPOSE

Functional results of index pollicisation are usually assessed by the clinical score of Percival. This score is based on elementary hand movements and does not reflect the function of the neo thumb in daily life activities. The aim of this study was to develop a new video-assisted scoring system based on daily life activities to assess index pollicisation functional outcomes.

METHODS

Twenty-two consecutive children, operated between 1998 and 2012, were examined with a mean of 77 months after surgery. The mean age at surgery was 34 months. Post-operative results were evaluated by a new video-assisted 14-point scoring system consisting of seven basic tasks that are frequently used in daily activities. The series of tasks was performed both on the request of the examiner and in real-life conditions with the use of a hidden camera. Each video recording was examined by three different examiners. Each examiner rated the video recordings three times, with an interval of one week between examinations. Inter- and intra-observer agreements were calculated.

RESULTS

Inter- and intra-observer agreements were excellent both on request (κ = 0.87 [0.84-0.97] for inter-observer agreement and 0.92 [0.82-0.98] for intra-observer agreement) and on hidden camera (κ = 0.83 [0.78-0.91] for inter-observer agreement and 0.89 [0.83-0.96] for intra-observer agreement). The results were significantly better on request than on hidden camera (p = 0.045). The correlation between the video-assisted scoring system and the Percival score was poor.

CONCLUSION

The video-assisted scoring system is a reliable tool to assess index pollicisation functional outcomes. The scoring system on hidden camera is more representative of the neo thumb use in daily life complex movements.

LEVEL OF EVIDENCE

Level IV.

Charge, Color, and Conformation: Spectroscopy on Isomer-Selected Peptide Ions

Monitoring the chromism induced by intramolecular hydrogen and charge transfers within proteins as well as the isomerization of both protein and cofactor is essential not only to understand photoactive signaling pathways but also to design targeted opto-switchable proteins. We used a dual-ion mobility drift tube coupled to a tunable picosecond laser to explore the optical and structural properties of a peptide chain bound to a chromophore—a prototype system allowing for a proton transfer coupled to conformational change. With the support of molecular dynamics and DFT calculations, we show how proton transfer between the peptide and its cofactor can dramatically modify the optical properties of the system and demonstrate that these changes can be triggered by collisional activation in the gas phase.

The structure of chromophore-grafted amyloid-β12–28 dimers in the gas-phase: FRET-experiment guided modelling

Theoretical modelling, ion mobility spectrometry and action-FRET experiments are combined to an experiment guided approach and used to elucidate the structure of chromophore-grafted amyloid-β_12–28 dimers in the gas-phase.

Chirality-dependent structuration of protonated or sodiated polyphenylalanines: IRMPD and ion mobility studies

Ion mobility experiments are combined with Infra-Red Multiple Photon Dissociation (IRMPD) spectroscopy and quantum chemical calculations for assessing the role of chirality in the structure of protonated and sodiated di- or tetra-peptides. Sodiated systems show a strong chirality dependence of the competition between Na(+)O and Na(+)π interactions. Chirality effects are more subtle in protonated systems and manifest themselves by differences in the secondary interactions such hydrogen bonds between neutral groups or those involving the aromatic rings.

Correction: Conformational changes in amyloid-beta (12-28) alloforms studied using action-FRET, IMS and molecular dynamics simulations

Correction for ‘Conformational changes in amyloid-beta (12–28) alloforms studied using action-FRET, IMS and molecular dynamics simulations’ by Steven Daly et al., Chem. Sci., 2015, 6, 5040–5047.

[Detection and surveillance of idiopathic scoliosis]

Detection and surveillance of idiopathic scoliosis. Spinal deformities are frequent in children. Detection on physical examination must be systematically performed especially in pre-puberty period because of the potential risk of progression. The main spinal pathology remains scoliosis, which affects 2 to 3% of the population. The presence of a rib hump is pathognomonic for the diagnosis of scoliosis. The diagnosis is confirmed by full-spine radiographs, on which a Cobb angle is > 10° and is associated to a vertebral rotation. Idiopathic scoliosis is the most frequent aetiology (80 to 90% of the cases). However, a secondary aetiology must be systematically evocated. The follow-up depends on the age of the patient and the severity of the deformity. A clinical and a radiological follow-up must be performed every 3 to 6 months and must be particularly close in younger patients.

Tandem ion mobility spectrometry coupled to laser excitation

This manuscript describes a new experimental setup that allows to perform tandem ion mobility spectrometry (IMS) measurements and which is coupled to a high resolution time-of-flight mass spectrometer. It consists of two 79 cm long drift tubes connected by a dual ion funnel assembly. The setup was built to permit laser irradiation of the ions in the transfer region between the two drift tubes. This geometry allows selecting ions according to their ion mobility in the first drift tube, to irradiate selected ions, and examine the ion mobility of the product ions in the second drift tube. Activation by collision is possible in the same region (between the two tubes) and between the second tube and the time-of-flight. IMS-IMS experiments on Ubiquitin are reported. We selected a given isomer of charge state +7 and explored its structural rearrangement following collisional activation between the two drift tubes. An example of IMS-laser-IMS experiment is reported on eosin Y, where laser irradiation was used to produce radical ions by electron photodetachment starting from doubly deprotonated species. This allowed measuring the collision cross section of the radical photo-product, which cannot be directly produced with an electrospray source.

Conformational changes in amyloid-beta (12-28) alloforms studied using action-FRET, IMS and molecular dynamics simulations

Small oligomers of the amyloid beta protein (Aβ) have been implicated as the neurotoxic agent leading to Alzheimer's disease, and in particular mutations in the hydrophobic core region comprising amino acids L17 to A21 have a large influence on the propensity for aggregate formation. It has been shown that the F19P alloform of Aβ forms small aggregates, but does not proceed to form large fibrils and plaques. In order to understand the origin of this behavior, the gas phase conformations for the different charge states of the wild-type 12-28 fragment of the amyloid beta and its F19P alloform were studied by a combination of action-FRET, ion-mobility spectrometry (IMS) and molecular dynamics simulations. Comparison of the experimental and theoretical action-FRET efficiencies and collision cross sections allowed the determination of the lowest energy conformational family for each alloform and charge state. For both alloforms, it was found that there is a change from globular to helical structure between the 3+ and 4+ charge states. Additional protonation to give 5+ and 6+ charge states caused unfolding of this helical motif, with the wild alloform showing β-turn like motifs and the F19P alloform random coil motifs. The presence of the helical to β-turn structural transition in the wild, but not the F19P, alloform may help to elucidate the origin of the large difference in aggregation behavior of the two alloforms.

Dynamic balance assessment during gait in spinal pathologies - a literature review

The role of the spine as a gait stabilizer is essential. Dynamic assessment, while walking, might provide complementary data to improve spinal deformity management. The aim of this paper was to review spine dynamic behavior and the various methods that have been used to assess gait dynamic balance in order to explore the consequences of spinal deformities while walking. A review was performed by obtaining publications from five electronic databases. All papers reporting pathological or non-pathological spine dynamic behavior during gait and dynamic balance assessment methods were included. Sixty articles were selected. Results varied widely according to pathologies, study conditions, and balance assessment techniques. Three methods assessing dynamic stability during gait were identified: local-orbital dynamic stability, tri-axial accelerometry, and dynamic stability margin. Data from conventional gait analysis techniques were established essentially for scoliosis and low back pain, but they do not assess specific consequences on gait dynamic balance. Three techniques investigate gait dynamic balance and have been validated in normal subjects. Further investigations need to be performed for validation in spinal pathologies as well as the value for clinical practice.

LEVEL OF EVIDENCE

Level IV.

Contribution of domain interface residues to the stability of antibody CH3 domain homodimers

Dimers of CH3 domains from human IgG1 were used to study the effect of mutations constructed at a domain-domain interface upon domain dissociation and unfolding, "complex stability". Alanine replacement mutants were constructed on one side of the interface for each of the sixteen interdomain contact residues by using a single-chain CH3 dimer in which the carboxyl terminus of one domain was joined to the amino terminus of the second domain via a (G4S)4 linker. Single-chain variants were expressed in Escherichia coli grown in a fermentor and recovered in yields of 6-90 mg L-1 by immobilized metal affinity chromatography. Guanidine hydrochloride-induced denaturation was used to follow domain dissociation and unfolding. Surprisingly, the linker did not perturb the complex stability for either the wild type or two destabilizing mutants. The CH3 domain dissociation and unfolding energetics are dominated by six contact residues where corresponding alanine mutations each destabilize the complex by >2.0 kcal mol-1. Five of these residues (T366, L368, F405, Y407, and K409) form a patch at the center of the interface and are located on the two internal antiparallel beta-strands. These energetically key residues are surrounded by 10 residues on the two external beta-strands whose contribution to complex stability is small (three have a Delta DeltaG of 1.1-1.3 kcal mol-1) or very small (seven have a Delta DeltaG of </=0.7 kcal mol-1). Thus, at the center of the CH3 structural interface there is a small "functional interface" of residues that make significant contributions to complex stability.